This invention relates to a rotary concentrator, wherein the volume of polluted air sent for final treatment is drastically reduced compared to the prior art.
The removal of pollutants in industrial air streams has caused the development of many pollution control devices. One commonly used device is a rotary concentrator. A rotary concentrator is basically a rotating adsorbent element. The element can be formed as either a disc or cylinder shape. Known adsorbents such as zeolites, or activated carbon are utilized in the rotating element.
Industrial air streams carrying impurities or pollutants are passed over the disk in a process cleaning stage, and the adsorbent material removes the impurities. A relatively clean air then leaves the disk. As the disk rotates, it passes through a desorption stage. Typically, the desorption stage occurs only over a very limited portion of the rotary cycle for the concentrator. Appropriate ducting blocks the gas to be cleaned from passing over the disk as it moves through the desorption stage. A hot gas is passed over the disk in the desorption stage to remove the impurities which have previously been deposited. Typically, the hot gas moves in the opposed direction over the disk to the direction taken by the gas to be cleaned.
The desorption air removes impurities such that the disk can leave the desorption section relatively clean of impurities. The disk is thus ready to remove additional impurities from gas as it moves out of the desorption stage and back into the process cleaning stage. In some cases the disc is cooled between the desorption and adsorption steps.
The desorption gas which leaves the desorption section carrying the pollutants is then sent to a final treatment stage wherein the pollutants are removed. The final treatment stage typically includes relatively expensive equipment when compared to the cost of the rotary concentrator. By utilizing the rotary concentrator, a much smaller volume of gas must be passed to the final control device.